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Fresh Water. Chapter 14. Section 1 Water and Its Properties. Objectives: Describe the amount of fresh water on earth Relate the structure of water molecules to the physical and chemical properties of water Explain why living things need water
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Fresh Water Chapter 14
Section 1 Water and Its Properties • Objectives: • Describe the amount of fresh water on earth • Relate the structure of water molecules to the physical and chemical properties of water • Explain why living things need water • Generalize about the role of energy in the water cycle
Skills Warm-up • Down the Drain • How much water do you use in a day? • Use the following estimates in your calculations: • Toilet – 20L/flush • Glass of water – 0.25L • Faucet – 15L/min • 5-minute shower – 75L
Earth’s Fresh Water • Earth is the water planet – ________ of surface covered by water • Total Water: • ________ salt water • ________ fresh water in glaciers/ice caps • ________ water is underground • _____ is in atmosphere • Whatever is left - surface fresh water
Put it in Perspective • Imagine ___________ of soda – represents all of earth’s water • Now imagine _______ of soda – represents the amount of usable fresh water • We must protect and conserve !
Properties of Water • 3 Phases of Matter • ________ – has its own shape because molecules are held together rigidly • _______ – takes shape of container because molecules not held together as closely • ____ – fills its container because molecules not held together
Properties of Water • Water is the only compound that occurs in all 3 ______ ___ _______ at ________ earth temperatures • Ice covered lake • Ice is water’s solid phase • Water underneath is the liquid phase • Water vapor above ice is the gas phase
Water Molecule • Water’s chemical formula is _______ • What does that mean? • Water is a _________ molecule – the hydrogen atoms have a slight __________ charge and the oxygen a slight __________ charge
Water Molecule • Since opposites attract: • The ___________ atoms from one water molecule are • Attracted to the __________ atoms from other water molecules • They “stick” together through ___________ __________
Physical Properties of Water • Water gains and loses heat energy _________ compared to other compounds • Heat is the energy of ___________ molecules • It takes ________ energy to separate polar water molecules and get them moving • Water also ________ ______
Physical Properties of Water • Normally a material’s solid phase is _______ than its liquid phase • But, water’s solid phase is ____ _______ • This is because water’s polar molecules can’t get too close together • Like charges _______ • That is why ice ______ on water
Physical Properties of Water • Water has ________ _______ – its surface is a skin-like layer • This occurs because water molecules _________ each other • Gives water droplets a __________ shape • Also causes light objects to ________
Chemical Properties of Water • Water is called the _______________________ • It can dissolve many other _____ substances • Think of all the things you drink (milk, lemonade, soda) that are mixtures of other things in water • This is also due to water molecules’ ______ – they attract other things and keep them in solution
Water Cycle • The water cycle is a _________________of evaporation and condensation that controls the distribution of the earth's water as it: • ____________from bodies of water • ____________ • ____________ • ____________to those bodies of water
Water Cycle • _____________– water vapor condenses into liquid water • _____________– liquid water is heated by sun’s energy to form water vapor • _____________– Water falls as rain, hail, sleet, or snow • ________– when water cannot soak into the ground – gravity pulls it downhill
Water and Living Things • _________ is essential for all living things • About _______ of your body weight is from water • You can survive ______ without food than without water • 3-5 days without water • Several weeks without food
Water and Living Things • We take in water by ________ and ________ • We release water in _____________, _____________, _____________, etc. • Water keeps us cool on hot days – heat energy from your hot skin evaporates watery sweat, cooling you off
Water and Living Things • ______ use water, along with carbon dioxide and light from the sun for ____________________ • _____________ – process by which water move up through a plant eventually exiting through tiny __________ in their leaves • _______ __________ of water return to the atmosphere by transpiration
Your Water Use • On average, each person in U.S. uses __________ of water/day – not including indirect uses
Your Water Use • If you include all indirect water uses – the average consumption is over ___________________ • Indirect water use can include: • 200,000L to ____________ • 800L to ________________ • 500L to ________________ • 4,000L to ______________
Your Water Use • Where does fresh water come from? • __________________ • __________________ • __________________ • __________________ • __________________ • All of these sources get their water from precipitation
How Do We Return Water • Water from crops and plants – direct ___________________ • Waste water from homes/businesses – must first go through a _____________ __________ • _____________– septic tank separates out wastes from clean water • _____________ – pipes to sewage treatment plant where water is filtered and cleaned
Activity • Discovery Education “Water Cycle Movie”
Review Questions • 1. Describe in your own words what fresh water is. How much of the earth’s water is fresh water? • 2. Explain how the structures of a water molecule relates to three properties of water. • 3. Write a general statement describing the role of the sun’s energy in the water cycle. • 4. Draw and label a diagram that traces the path of a water molecule through the water cycle.
Section 2 Surface Water • Objectives: • Describe three ways in which fresh water exists on the surface of the earth • Describe a water shed and its drainage systems • Predict what life on earth might be like if freshwater didn’t accumulate on earth’s surface
Skills Warm-up • Rain Tracks • Based on your observations, what happens to rainfall that falls on buildings where you live? • What could happen that might change the path of the rainwater?
Different Landscapes • Some areas are forests, some are deserts • Areas are different because of the ___________ ______________ there • The amount of water in an area depends on the amount of ______________________
Running Water • Water from rain or melted snow can ______ into ground, ____________, or flow over as _________ • Runoff forms rills and gullies to flow into streams and rivers • Running water carries water back to _______ and lets water evaporate into air
Streams and Rivers • Streams flow into rivers and rivers flow into oceans forming a _____________________ • From above, a drainage system can form a tree-like pattern • ______________ – a small stream that flows into a larger one • ____________ drainage systems have many tributaries
Streams and Rivers • Rivers give fresh __________________ • Rivers transport __________________ • Land along riverbanks is good for ____________ because there is plenty of water and nutrient-rich soil
Watersheds • The surrounding land area that supplies ______ to the streams of a drainage system • Can be less than 1 km to thousands of km • Watersheds that supply runoff to different drainage systems are separated by a ridge called a _____________ • Rocky Mountains make up the _______________ ______________________ • Streams to the _______ drain to the Atlantic Ocean • Streams to the _______ drain to the Pacific Ocean
Standing Water • When running water reaches a low area in a drainage system, it stops flowing • This low area fills with water to become • ________ – form in large, deep depressions – sunlight doesn’t reach bottom • ________ – form in small depressions – sunlight reaches bottom • ________ – artificial lake built to store fresh water or prevent flooding
Frozen Water • Most of the world’s fresh water is _________ • Near the poles, permanent __________ form • Snowfields turn into _____________ • During short summers, some of the ice _______ supplying fresh water to many areas
The Wandering River • ___________ River is the 3rd longest in the world – has >200 tributaries and 4th largest watershed • It hasn’t always been in the _______________ • About every _________ years it changes course, cutting a new ____________ and abandoning its old one
The Wandering River • In Louisiana, the Mississippi has been trying to change its course __________ to the Atchafalaya River • If this happened, the port of ____________ would dry up and the cities near the Atchafalaya would flood • The army corps of engineers began a huge flood-control project
Review Questions • 1. What are three ways in which fresh water exists on the earth’s surface? • 2. Describe a watershed and drainage system. • 3. What do you think life on earth would be like if there were ne fresh water on the surface?
Section 3 Water Beneath the Surface • Objectives: • Explain what forms groundwater and describe groundwater zones • Describe the movements and activities of groundwater • Predict changes in groundwater • Classify earth materials by permeability
Skills Warm-up • Taking in Water • What happens when you water a potted plant? • Where does the water go? • On a global scale, a huge amount of precipitation soaks into the ground. • The amount of water underground is more than all the world’s rivers and lakes combined.